Polúmētis Thó̱rakas (Resourceful Cuirass): God-Forged Armor
CLASS: Anti-Unit (Self)
RANK: B+
A golden cuirass emblazoned with a crest of the boar; it is the most trusted armor of Diomedes, forged by the Greek blacksmith god Hephaestus. It is a Divine Construct filled with a divine magical presence. Even those who lack the skill to sense and perceive mana would feel a divine essence emanating from the armor, as if there was a god present in the flesh among mortals. It was referred to as impenetrable during Diomedes' usage of the armor during the Trojan War. This defensive, continuously active Noble Phantasm exhibits a unique protection that differs from other defensive Noble Phantasms. Its defensive strength feeds on the physical and magical prowess of those around Diomedes, regardless if they are friend or foe to the hero. It reduces the Strength, Endurance, Agility and Mana parameters by one rank of all those nearby, and these stolen parameters are converted into the armor’s defensive strength, added to the armor’s base defensive level. Naturally, the cumulative effect brought upon as a result of being in a battlefield where many warriors are gathered and fighting, such as in the Trojan War, was an absurdity. However, there is a limit to its maximum defensive strength, only capable of reaching defenses on a level of a B+ Noble Phantasm when fighting against and/or among up to four other Servants (due to the modern era's lack of Mystery, the armor cannot use its full power). Additionally, this protection only extends to the armament Diomedes has on, and will not extend that protection over his exposed flesh. And furthermore, if somehow the divine essence of the magical energy residing inside the armor is suppressed or removed, such as through an ability that reduces Mystery for example, then the protection will be disabled.
There is a hidden trump card to this Noble Phantasm, and the ability is referred to as the 'Diomedian Swap', referring to the famous anecdote where Diomedes swapped one of his lesser quality armor with a Trojan's armor that is worth tenfold over his traded armor. This ability only works on other armor-class/defensive Skills or Noble Phantasms and one of two conditions must be fulfilled: either Diomedes witness the defensive Skill or Noble Phantasm's ability in action, or Diomedes knows the name of the Skill or Noble Phantasm without seeing the ability in action. Once the required knowledge is obtained, Diomedes can initiate the transfer process by saying "With the Diomedian Swap, I hereby switch my Polúmētis Thó̱rakas with [Servant's Skill or Noble Phantasm]", and the defensive ability of his Noble Phantasm will be switched with the defensive ability of the specified Skill or Noble Phantasm of the other target. There is no mana cost for swapping his Noble Phantasm with a target's defensive Skill. This ability switch is permanent, and the only way to revert it is if Diomedes dies, he willfully cancels it, or the crest of the boar on his golden armor is destroyed. Furthermore, Diomedes retains the inherent weaknesses of his own golden armor rather than getting the weaknesses of the specified defensive Skill or Noble Phantasm that he obtained from the target. He cannot use this hidden ability more than once unless he cancels the stolen ability he had obtained before.
Furthermore, this armor grants Diomedes a Divinity Skill of Rank B for as long as he wears it due to its divine magical presence. Only the armor is treated as the ‘Divine Spirit’, and not Diomedes’ mortal body. However, any of Diomedes’ actions are counted as the “actions of a Divine Spirit” due to his legend (While fully mortal back in his past life, Diomedes was made an immortal god at the end of his lifespan by Athena, further deified as a divine being by his worshipers afterwards), even if some of them are done with his fully mortal body, and any of his attacks has the effect of ‘purge defense’.
Aspída ti̱s Aito̱likí̱s Kápros (Shield of the Aetolian Boar): Flamethrower of the War Goddess
CLASS: Anti-Army
RANK: A
A silver round shield bearing the mark of the Aetolian Boar; while it is a shield, the Noble Phantasm ability does not emphasis its usage as a defensive armament. Rather, by calling out the name of this Noble Phantasm, Diomedes can use this shield to unleash a flaring stream of divine fire from the emblazoned boar's mark in the form of a wide-ranging and destructive flamethrower meant for Anti-Army usage. The divine origin of the fire comes from Athena, the Greek war goddess, who interjected her divine magical energy into Diomedes' shield for offensive usage back in the Trojan War. The fire is of the highest class, containing immeasurable heat that is meant to burn mortal flesh to the bones and within. However, it is not meant to be used on those of divine origin, so those with Divinity or Divine Protection or other similar divine aptitude-related Skills would take damage comparable to a B-Rank Noble Phantasm instead.
Mana usage is heightened if this Noble Phantasm was used to unleash a continuous stream of fire in the form of a flamethrower. On the other hand, this Noble Phantasm can unleash a brief burst of fire in the form of a fireball instead, which is much more mana-efficient should Diomedes decide that the flamethrower option is not necessary; this alternative attack does not require the Noble Phantasm's name to be called upon. Additionally, this Noble Phantasm can unleash a homing attack, but a set-up is required. The set-up is done by marking someone with the mark of the Aetolian Boar through successfully ramming the shield into the desired target. The eyes of the Aetolian Boar on the shield would light up with flaring divine fire, indicating contact was successful. Then, Diomedes calls upon the name of this Noble Phantasm after a successful mark, and the released fire, taking on the form of a narrow yet still destructive flamethrower, would relentlessly pursue the marked target until the life of the 'prey' fades away from the flames.
Athi̱naïkí̱ Orgí̱ (Athenian Wrath): Intervention-Reversing Spear
CLASS: Anti-Divine
RANK: B
This Noble Phantasm is the thrown attack of Diomedes' spear that once harmed full-fledged gods in the middle of the Trojan War. The attack takes on the form of a simple, straight-forward spear throw done with all of Diomedes' strength, yet the spear throw can home in on its target due to how Athena influenced it in the past during the war by interjecting her divine magical energy into it to make it a homing projectile. The target is chosen by Diomedes throwing the spear towards him or her with pinpoint accuracy; if Diomedes misses his desired target, or if the target is not actually divine, then the spear tracks the nearest divine target unless that particular target is not present in the conflict. Due to its properties of harming a god before, it can ignore all Divine Protection of the target to ensure harm is done to the divine target. However, this Noble Phantasm falls one step short of being a god-slaying Noble Phantasm, and thus, the ability can never kill; if the target does dies, it means that he or she has actually died from the damage of the spear throw.
The spear throw, imbued with divine energy, is unremarkable by itself, simply a Noble Phantasm that does a B-Rank worth of damage (or roughly an A+ physical damage). It is merely a medium for the Noble Phantasm's ability to activate, which it does upon inflicting a wound to a divine target. Any wound caused by this Noble Phantasm would incur a seal on a percentage of the target's Skills and Noble Phantasms collectively, the percentage varying based on the target's Divinity rank, from 20% on those with E-Rank Divinity to 100% on those with A-Rank Divinity and above. For seals with a percentage lower than the full 100%, what Skills and Noble Phantasms are sealed first would be those that could potentially influence or intervene in the ongoing conflict; in other words, abilities that can still cause interference within the battle even if the target has left the battlefield. Once those Skills and Noble Phantasms are sealed, and if more sealing is required, the other remaining non-intervening Skills and Noble Phantasms would be randomly chosen to be sealed.
The purpose of the seal is to force the target to flee the battle, just as how the Greek gods have left the battlefield of the Trojan War upon being wounded by Diomedes' spear. The target can stay behind and still adamantly fight, but they are at a disadvantage with the seal affecting their arsenal. The seal can only be unlocked when the wound 'naturally' heals, and the wound would not start healing until they are out of combat for at least half a day. However, if the target is forced into a different battle within that time period, the seal temporarily unlocks their Skills and Noble Phantasms, but the wound would still not be able to be healed, naturally or otherwise.
Agapiména tis Athinás (Athena's Favorite): War Goddess's Patronage
CLASS: Anti-Unit
RANK: EX
A Noble Phantasm hidden from Diomedes' Servant status page. It is the Noble Phantasm that represents Athena's devotion and patronage to Diomedes. It is a continuously active-type Noble Phantasm that actually brings forth Athena from the Throne of Gods, and this Noble Phantasm represents Athena's presence in the Holy Grail War. While normally impossible to summon an authentic Divine Spirit, in order for this scenario to become possible, Athena's rank as a spirit has to be temporarily degraded from the Divine Spirit rank to the Heroic Spirit rank, and the circumstances of her accompaniment is made possible largely due to Diomedes' legend as the most favored warrior of all the warriors Athena has favored before back in Greek Mythology, as well as due to the situations that unfolded from their tight-knit bond.
In this state, Athena is considered a Servant that is branched off from her Heroic Spirit self, and she is always invisible to everyone's eyes, including Diomedes'. Her presence is largely dormant and inactive, and unless there is a user with an ability to detect presences or has highly keen perceptions that can allow one to discern an invisible presence, her presence is generally undetectable. For as long as Athena is nearby Diomedes, the latter will be given the Divine Protection Skill, his Bravery Skill will receive a rank-up, and he is able to use the Aspída ti̱s Aito̱likí̱s Kápros and Athi̱naïkí̱ Orgí̱ Noble Phantasms. Additionally, the aforementioned Noble Phantasms cannot be sealed and is always able to be activated, regardless of the situations presented and even if Diomedes lacks the sufficient mana. After all, it is Athena's interjection of her own magical energy that allows them to be used, and the seals must target Athena herself and be resolved around her nature as a Divine Spirit and the Goddess of War in order to successfully seal the aforementioned Noble Phantasms' usage.
Aside from the benefits listed above, Athena can independently act if she so chooses and does not need to remain passive. However, leaving Diomedes' side in terms of their physical distances to each other will disable all the listed benefits. Also, if Athena becomes more active, her presence is more easily detectable. Even then, not many can discern and fend off an invisible Servant attacking them from out of nowhere. Athena possesses her own sets of parameters and can also invoke the Aspída ti̱s Aito̱likí̱s Kápros and Athi̱naïkí̱ Orgí̱ Noble Phantasms independently from Diomedes and by herself, although she must physically wield the Noble Phantasms. She also possesses the Hades's Cap of Invisibility Noble Phantasm, the source of her invisibility.